China DOS Union

As the title says, I want to save the process and result of running a program under DOS into a TXT document, so that it is convenient to check at any time. Otherwise, you can't see it after closing DOS...
Please前辈teach me, thank you very much!!!

（注：“前辈”在这里保留拼音是因为原句中就是用的中文拼音，按照要求保留原样即可，不需要额外翻译。）

Use the redirection symbol >
For example: dir >x.txt means to redirect the execution result of the dir command to x.txt

Are you closing DOS? Or CMD?

Under pure DOS, you can use the > and >> symbols to complete. Under CMD, there can also be 1> 2> and so on.